Stay-bolt construction for steam-boilers.



J. H. MGOLOY & A. M. BROWN.

STAY BO'LT CONSTRUCTION FOR STEAM BOILERS.

APPLICATION FILED SEPT. 18,1911.

1,025,706. Patentgd May 7, 1912.

INVENTO S ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN 11. McCLOY, orcnAnA'rm, AND ALnxANnEa'm. nnown, or

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OAKMONT,

STAY-BOLT CONSTRUCTION FOR STEAM-BOILERS.

Specification of Letters Patent.

Patented May 7, 1912.

Application filed September 18, 1911. Serial No. 849,818.

staybolt construction for steam boilers, and

has for its principal object the provision of a construction which will provide a tight steam joint, which will provide for flexibility between the boiler sheets, which will be relatively inexpensive and of great strength and durability, and by means of which inspection of the condition of the bolt can be readily had.

To these and other ends, the nature of which will be readily understood as our invention is hereinafter disclosed, said invention consists in the improved construction and combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims.

In the accompanying drawings, in which similar reference characters indicate similar parts in each of the views,-Figure 1 is a sectional view showing the two sheets of a boiler connected together by the stay-bolt construction forming our invention, the bolt being shown in elevation.- Fig. 2 is a side elevation of the socket-sleeve. Fig. 3 is an end view of the same. Fig. 4 is an end view of one form of bolt. Fig. 5 is a view similar to Fig. 4 but showing a different form of bolt-turning head. Fig. 6 is a sectional view showing a modified form of cap.

In the drawings, 10 represents the inner or fire-box sheet of a boiler, and 11 the outer or shell sheet, the space between these sheets forming the steam or water space ofthe boiler.

12 designates a stay-bolt having its inner end threaded, as at 13, and its outer end headed. The head of the bolt is truly spherical between two parallel lines forming chords on opposite sides of the center,

of the spherical portion. To 'form the line 15, which corresponds to the main outer face of the bolt-head, the spherical portion is cut away on opposite sides, as at 16 in 5, or on four sides, as indicated at 17 in Fig. 4, leaving a part 18, which may be employed in connection with a wrench orother tool for the purpose of turning the bolt in placing it in position. If desired,

the end of the bolt may also be provided with a small depression 19 for a purpose presently described.

20 designates a socket-sleeve externally threaded, as at 21, and having its interior formed with a spherical seat 22 adapted to be strictly compleme'ntal to the inner spherical portion of the bolt-head, the seat being formed at the inner end of the sleeve, the

outer end of the sleeve having its inner periphery formed to permit the free passage of the bolt-head therethrough. The sleeve is of a length to provide a space between the head 9 the bolt and the outer end of the sleeve-when the arts are assembled, and for the urpose of forming a relatively tight threa- .d connection with the sheet 11, the inner end, of the shell has its screwthreads preferably tapered inwardly.

25 designates a cap which is adapted to be threaded on to the outer end of the sleeve 20. This cap may be of the form shown in Fig. 1 but we prefer to employ that shown in Fig; 6, in which a plug 26 is threaded centrally of the cap, said plug being of a size to permit ready inspection within the socket when the plug is removed.

As will be seen by reference to Fig. 1, the spherical head portion and the seat 22 are relatively formed so as to provide for a small extension of the spherical head inwardly beyond the plane of the inner end of the sleeve. As the seat and spherical member are formed with a ground joint, the seat extending to the inner end of the sleeve, it will be readily understood that flexibility of the bolt will be provided without the formation of any cavities external of the bolt or internal of the sleeve to which the water or steam can gain access. This is a positive advantage in that the incrustation or the deposit of sediment at the joint is eliminated, thus preventing the joint becoming affected by the action of the contents of the boiler, thereby eliminating one of the principal causes for the breaking of stay-bolts. The joint between the head and seat being a ground one, provides for substantially absolute tightness in this respect. Furthermore, by arranging the parts so that the inner end of the spherical port-ion represented by the line 14 is well inside of the end of the sleeve, we are able to provide for the use of stay-bolts having their bodyportions of different diameters, it being the purpose to make the sleeve and bolt-head of uniform diameters in connection with all sizes of bolts. This is of especial advantage in that, for instance, the original bolt may have a smaller diameter, providing a threading of the inner sheet 10 complemental to the threading of such bolt. When it is necessary to change bolts, the threads in the sheet 10 are enlarged to receive a bolt of larger diameter and which, can be dropped into the socket which is already in position and the proper Connection made; suflicient flexibility is provided by this construction with substantially no liability of a cavity being formed under such flexible movements.

Breakage of the stay-bolt will generally cause the outer end to move on the socket with the broken end dropping; as this changes the position of the outer end 18, such breaking will be readily detected. Should, however, the surface of the bolt be incrusted to an extent which would prevent such movement of the broken end, or if the fracture were such as to prevent the dropping of such end, a removal of the cap or preferably of the plug 26 would permit ac cess to be had to the interior of the sleeve, whereupon a suitable tool placed within the depression 19 and placed under pressure in various directions, would cause the broken end to be moved and thus indicate the fact that the bolt was broken.

By forming the end of the bolt in the manner indicated, the bolt can be readily turned by means of a wrench or similar tool without liability of twisting or affecting the shape of the spherical. portion of the head.

lVhile We have herein shown and described a preferred embodiment of our invention, we reserve the right to make such changes and modifications therein as may be found necessary under the exigencies of use, in so far as they may fall within the spirit and scope of the invention as expressed in the accompanying claims.

Having thus described our invention, what we claim as new is 1. In combination, a stay-bolt, a socketsleeve, and a cap, said bolt having a head integral therewith and formed spherical between two parallel planes intersecting the bolt axis at right angles, said sleeve having a seat extending to the inner end of the sleeve and formed complemental to the spherical port-ion of the head, the inner plane of the spherical portion being beyond the sleeve end to provide an exposed projecting portion of the spherical head when assembled, the relative arrangement of head and sleeve seat forming a joint free from cavities at the inner end of the sleeve, said cap being threaded to said sleeve.

2. In combination, a stay-bolt, a socketsleeve, and a cap, said bolt having a head integral therewith andformed spherical between two parallel planes intersecting the bolt axis at right angles, said sleeve having a seat extending to the inner end of the sleeve and formed complemental to the spherical portion of the head, the inner plane of the spherical portion being beyond the sleeve end to provide an exposed projecting portion of the spherical head when assembled, the relative arrangement of head and sleeve seat forming a joint free from cavities at the inner end of the sleeve, said cap being threaded to said sleeve, said bolt head having its outer end beyond the outer plane of the spherical portion reduced to form a wrench-hold.

3. In combination, a stay-bolt. a socketsleeve, and a cap, said bolt having a head integral therewith and formed spherical between two parallel planes intersecting the bolt axis at right angles, said sleeve having a seat extending to the inner end of the sleeve and formed complemental to the spherical portion of the head, the inner plane of the spherical portion being beyond the-sleeve end to provide an exposed projecting portion of the spherical head when assembled, the relative arrangement of head and sleeve seat forming a joint free from cavities at the inner end of the sleeve, said cap being threaded to said sleeve, said bolt head having its outer end beyond the outer plane of the spherical portion reduced to form a wrench-hold, said cap having a removable plug opposite the wrench-hold to permit access to the bolt head.

In testimony whereof we aflix our signatures in the presence of two witnesses.

JOHN H. MCCLOY. ALEXANDER M. BROWN.

Witnesses:

MAX H. SROLOVITZ, CHRISTINA T. H001). 

